Transcript Journal Club Alcohol, Other Drugs, and Health: Current Evidence July–August 2009 www.aodhealth.org Featured Article Alcohol Use and Risk of Pancreatic Cancer: The NIH-AARP Diet and Health Study Jiao.

Journal Club
Alcohol, Other Drugs, and Health: Current Evidence
July–August 2009
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Featured Article
Alcohol Use and Risk of
Pancreatic Cancer:
The NIH-AARP Diet and
Health Study
Jiao L, et al. Am J Epidemiol. 2009;169(9):1043–1051.
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Study Objective
• To determine the relationship between
alcohol use and risk of pancreatic cancer.
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Study Design
• Prospective cohort of 470,681 participants
from the US National Institutes of Health
(NIH)-AARP Diet and Health Study who were
aged 50–71 years between 1995–1996.
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Assessing Validity of an
Article About Harm
• Are the results valid?
• What are the results?
• How can I apply the results to
patient care?
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Are the Results Valid?
• Did the investigators demonstrate similarity in all
known determinants of outcomes? Did they
adjust for differences in the analysis?
• Were exposed patients equally likely to be
identified in the two groups?
• Were the outcomes measured in the same way in
the groups being compared?
• Was follow-up sufficiently complete?
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Did the investigators demonstrate similarity in
all known determinants of outcomes? Did they
adjust for differences in the analysis?
• Yes.
– The analysis used multivariable Cox proportional
hazards regression models to adjust for major
potential confounders. The final models were
adjusted for gender; smoking history; daily energy
(k/cal), saturated fat, red meat, and folate intake;
body mass index; physical activity; and self-reported
history of diabetes.
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Were exposed patients equally likely
to be identified in the groups?
 Yes.
– All participants were prospectively queried about
alcohol use for the 12 months prior to baseline;
therefore, there should be no differential
ascertainment of alcohol exposure.
– The exposure was presumed to be static, and
those who reported no alcohol consumption may
have included former drinkers.
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Were the outcomes measured in the
same way in the groups being compared?

Subjects were contacted on a regular basis
as part of the observational study, but there
were no procedures for active surveillance
of pancreatic cancer.

Incident pancreatic cancer outcomes were
determined through state cancer registries.
Fatal cases were determined through
linkage with the National Death Index.
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Was follow-up sufficiently complete?
• Approximately 4% of participants were lost
to follow-up.
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What are the Results?
• How strong is the association between
exposure and outcomes?
• How precise is the estimate of the risk?
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How strong is the association between
exposure and outcome?
How precise is the estimate of the risk?
• Beverage-specific effects revealed no increase in
risk for consumers of any amounts of beer or wine
or for consumers of liquor up to 3 drinks per day.
• Compared with light drinkers, the RR of
developing pancreatic cancer was
– 1.45 (95% confidence interval (CI): 1.17, 1.80) in subjects
who drank ≥3 drinks of beer or wine per day;
– 1.62 (95% CI: 1.24, 2.10) in subjects who drank ≥3
drinks of liquor per day; and
– 1.41 (95% CI: 1.01, 2.00) in subjects who had quit
smoking 10 or more years earlier.
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How Can I Apply the Results to
Patient Care?
• Were the study patients similar to the patients
in my practice?
• Was the duration of follow-up adequate?
• What was the magnitude of the risk?
• Should I attempt to stop the exposure?
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Were the study patients similar to the
patients in my practice?
• The sample included 470,681 men and women
aged 50–71 years from 6 US states (California,
Florida, Louisiana, New Jersey, North Carolina,
and Pennsylvania and 2 US metropolitan areas
(Atlanta and Detroit).
• Patients with cancer or extreme dietary intake
(>2 interquartile ranges above the 75th or
below the 25th percentile of Box-Cox logtransformed energy intake) were excluded.
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Was the duration of follow-up adequate?
• Average follow-up time was 7.3 years, which may
not be long enough to establish a strict causal
relationship unless one assumes that baseline
drinking approximates adult lifetime alcohol
exposure.
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What was the magnitude of the risk?
• Consuming >3 drinks of alcohol or liquor per
day was associated with an approximately
50% increase in risk for pancreatic cancer.
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Should I attempt to stop the exposure?
• The potential additive risk should be
discussed with individuals in light of other
known risk factors for pancreatic cancer
including tobacco use, diet, and high caloric
intake.
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